This invention relates to an automatic, self-propelled swimming pool cleaner.
Cleaners of this kind fall basically into two major classes: electrically operated cleaners and hydraulically operated cleaners.
A common requirement to both cleaner classes is that they should allow for changes in their travel paths across the pool bottom and side walls such that the whole pool surface can be cleaned.
In addition, the cleaner is to readily go over such obstacles as edges, corners, fittings, and any other surface discontinuities met on the pool surfaces being cleaned.
Examples of hydraulically operated cleaners are described in U.S. Pat. No. 4,560,418 and German Patent No. 2612043. Examples of electrically operated cleaners are described in European Patent No. 257006 and French Patent Application No. 2584442.
Electric cleaners benefit, in comparison with hydraulic cleaners, from more convenient handling of their directional control because changes in direction and deviations from a set travel path can be programmed through electric signals sent to the cleaner drive motors. On the other hand, their construction is more complex than that of hydraulic cleaners, and watertight compartments must be arranged for their electric components.
Irrespective of how easily the directional control of electric cleaners can be provided, if the program that handles such control cannot be altered by the user, it may occur that a preset control routine fails to fit different pool designs.
For these and other reasons, fully hydraulically operated cleaners have met widespread commercial acceptance despite their lower flexibility.
Among the reasons for such acceptance is that the foul matter removed by the cleaner is at once taken away from the pool and collected in the main filtering system, which affords increased range for the cleaner and fully safe operation thereof, as well as decreased cost.